Mixing devices are in wide use in industry, and many mixing devices include a large vessel which contains a liquid to be mixed, and a typically vertical impeller shaft running down some or all of the vertical length inside the vessel. The impeller shaft is typically rotatably driven by a motor, usually located at the top of the vessel, and at one or several locations on the length of the shaft radially extending impellers are mounted which have paddles or blade type features along some or all of the length and which mix and/or otherwise impart energy to the fluid inside the vessel.
In some instances, a motor and drive assembly along with some sealing arrangement are mounted at a top opening of the vessel, and the shaft is suspended, so that it hangs down from this motor with its lower end being a free end spaced above the bottom of the vessel. In the case of a long shaft, this type of arrangement may also include one or more “steady bearings”, which are radially mounted supports that maintain the shaft in its axial position. Some shafts will also have a bottom bearing mounted to the bottom of the vessel, so that the lower stub of the shaft is rotatably supported at the bottom inside of the vessel.
In some instances, the impeller components are welded directly onto the shaft in order to extend radially outward from the shaft. This arrangement has a disadvantage that it is relatively permanent and once an axial location is selected and the blade is mounted at that location, it is now difficult to then go back and adjust the blade location without time consuming and disadvantageous further welding processes. Therefore, these welded systems are not very adjustable in the field. Further, performing a since welding process at the final installation location may be undesirable, the entire shaft and impeller assembly must sometimes be shipped in their final configuration, which can be bulky. Therefore, these conventional designs also do not benefit from being shipped broken down and assembled at their final installation site easily.
Accordingly, there is a need in the art for a apparatus and method which can be easily mounted onto a shaft and at a desired axial location, and which can also be easily adjusted to a different axial location and/or removed entirely when desired.